Australian Journal of Botany (1997) 45, 905-917

B.L. Shearer, C.E. Crane, R.G. Fairman and M.J. Grant (1997)
Occurrence of Armillaria luteobubalina and pathogen-mediated changes in coastal dune vegetation of south-western Australia
Australian Journal of Botany 45 (5), 905-917
Abstract: Sixty-two Armillaria luteobubalina Watling and Kile disease centres were assessed along the coast from near Cervantes, 160 km north-west of Perth, to Cape Arid, 120 km east of Esperance. Disease centres ranged from 0.02 to 6.5 ha in size (mean ± s.e., 1.7 ± 0.2 ha). Most disease centres were active, with mainly old deaths occurring in only 7% of centres. Impact was low in only 3% of centres. Disease centres mainly occurred on calcareous sands of Holocene dune systems. Susceptible hosts from the Proteaceae, Mimosaceae and Myrtaceae tended to bedominant small trees or shrubs and their death resulted in centres composed mainly of sedges or small shrubs and ground-cover species from a range of families. Percentage cover of susceptible plant species was significantly less in disease centres than adjacent healthy areas. Cover of resistant species tended to be greater in disease centres than adjacent healthy areas, although differences were not significant. In association with changes in community structure, infection resulted in more bare ground in disease centres than amongst healthy vegetation. Infection had minimal effect on species richness.The mortality progress curve for the susceptible species Dryandra sessilis (Knight) Domin increased at a mean apparent infection rate of 0.31 ± s.e. 0.12 year^-1. A disease centre extended at the rate of 0.004 ha year^-1 between 1964 and 1983 and 0.07 ha year^-1 during the period 1981-1989. Disease extension per year was not correlated with yearly rainfall. Threatened taxa killed by A. luteobubalina included the rare and endangered Banksia brownii Baxter ex R.Br., B. occidentalis R.Br. subsp.formosa Hopper, and B. verticillata R.Br. This is the first report ofdisease significantly altering the structure and composition of coastal vegetation of south-western Australia. Armillaria luteobubalina is a significant additional, and hitherto unrecognised, selection pressure on coastal dune vegetation communities, and an important consideration in their management and conservation.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Bryan L. Shearer, Colin Crane

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Armillaria luteobubalina	Banksia (crop)	Australia (Western)